1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
|
/****************************************************************************
**
** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:FDL$
** GNU Free Documentation License
** Alternatively, this file may be used under the terms of the GNU Free
** Documentation License version 1.3 as published by the Free Software
** Foundation and appearing in the file included in the packaging of
** this file.
**
** Other Usage
** Alternatively, this file may be used in accordance with the terms
** and conditions contained in a signed written agreement between you
** and Nokia.
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
/*!
\class QPair
\brief The QPair class is a template class that stores a pair of items.
\ingroup tools
QPair\<T1, T2\> can be used in your application if the STL \c
pair type is not available. It stores one value of type T1 and
one value of type T2. It can be used as a return value for a
function that needs to return two values, or as the value type of
a \l{Container classes}{generic container}.
Here's an example of a QPair that stores one QString and one \c
double value:
\snippet doc/src/snippets/code/doc_src_qpair.cpp 0
The components are accessible as public data members called \l
first and \l second. For example:
\snippet doc/src/snippets/code/doc_src_qpair.cpp 1
QPair's template data types (T1 and T2) must be \l{assignable
data types}. You cannot, for example, store a QWidget as a value;
instead, store a QWidget *. A few functions have additional
requirements; these requirements are documented on a per-function
basis.
\sa {Container Classes}
*/
/*! \typedef QPair::first_type
The type of the first element in the pair (T1).
\sa first
*/
/*! \typedef QPair::second_type
The type of the second element in the pair (T2).
\sa second
*/
/*! \variable QPair::first
The first element in the pair.
*/
/*! \variable QPair::second
The second element in the pair.
*/
/*! \fn QPair::QPair()
Constructs an empty pair. The \c first and \c second elements are
initialized with \l{default-constructed values}.
*/
/*!
\fn QPair::QPair(const T1 &value1, const T2 &value2)
Constructs a pair and initializes the \c first element with \a
value1 and the \c second element with \a value2.
\sa qMakePair()
*/
/*!
\fn QPair<T1, T2> &QPair::operator=(const QPair<T1, T2> &other)
Assigns \a other to this pair.
*/
/*! \fn bool operator==(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2)
\relates QPair
Returns true if \a p1 is equal to \a p2; otherwise returns false.
Two pairs compare equal if their \c first data members compare
equal and if their \c second data members compare equal.
This function requires the T1 and T2 types to have an
implementation of \c operator==().
*/
/*! \fn bool operator!=(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2)
\relates QPair
Returns true if \a p1 is not equal to \a p2; otherwise returns
false. Two pairs compare as not equal if their \c first data
members are not equal or if their \c second data members are not
equal.
This function requires the T1 and T2 types to have an
implementation of \c operator==().
*/
/*! \fn bool operator<(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2)
\relates QPair
Returns true if \a p1 is less than \a p2; otherwise returns
false. The comparison is done on the \c first members of \a p1
and \a p2; if they compare equal, the \c second members are
compared to break the tie.
This function requires the T1 and T2 types to have an
implementation of \c operator<().
*/
/*! \fn bool operator>(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2)
\relates QPair
Returns true if \a p1 is greater than \a p2; otherwise returns
false. The comparison is done on the \c first members of \a p1
and \a p2; if they compare equal, the \c second members are
compared to break the tie.
This function requires the T1 and T2 types to have an
implementation of \c operator<().
*/
/*! \fn bool operator<=(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2)
\relates QPair
Returns true if \a p1 is less than or equal to \a p2; otherwise
returns false. The comparison is done on the \c first members of
\a p1 and \a p2; if they compare equal, the \c second members are
compared to break the tie.
This function requires the T1 and T2 types to have an
implementation of \c operator<().
*/
/*! \fn bool operator>=(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2)
\relates QPair
Returns true if \a p1 is greater than or equal to \a p2;
otherwise returns false. The comparison is done on the \c first
members of \a p1 and \a p2; if they compare equal, the \c second
members are compared to break the tie.
This function requires the T1 and T2 types to have an
implementation of \c operator<().
*/
/*!
\fn QPair<T1, T2> qMakePair(const T1 &value1, const T2 &value2)
\relates QPair
Returns a QPair\<T1, T2\> that contains \a value1 and \a value2.
Example:
\snippet doc/src/snippets/code/doc_src_qpair.cpp 2
This is equivalent to QPair<T1, T2>(\a value1, \a value2), but
usually requires less typing.
*/
/*! \fn QDataStream &operator>>(QDataStream &in, QPair<T1, T2> &pair)
\relates QPair
Reads a pair from stream \a in into \a pair.
This function requires the T1 and T2 types to implement \c operator>>().
\sa {Serializing Qt Data Types}
*/
/*! \fn QDataStream &operator<<(QDataStream &out, const QPair<T1, T2> &pair)
\relates QPair
Writes the pair \a pair to stream \a out.
This function requires the T1 and T2 types to implement \c operator<<().
\sa {Serializing Qt Data Types}
*/
|
